Motion control software has a structure in which motion tasks configuring the motion control software wake up every cycle required by each task to execute the motion control software. In this case, in each task, an interval between the wakeup times needs to be accurately matched with the cycle, but the intervals may not be uniform according to an operating system. This causes a task activation jitter.
In order to reduce the task activation jitter in a Linux operating system, a PREEMPT_RT real-time patch is proposed, and a structure in which a real-time operating system and a non-real-time operating system (e.g. Linux) are executed on a dual operating system structure such as Xenomai or RTAI, that is, a single processor is proposed.
The task activation jitter is propagated and accumulated to next steps of the pipeline to eventually cause actuation moments of each motor to be temporally shaken. Further, the task activation jitter increases an end-to-end delay time of the motion task and acts as an obstacle to shortening the cycle of the task.
The PREEMPT_RT patch and the dual operating system structure need to correct or re-create all device drivers used in the operating system, in order to reduce the task activation jitter of the motion control software.
In Korea Patent Publication No. 2002-0068651 (title of invention: Extended task scheduling algorithm considering execution of XIP task and regeneration of flash memory), a measure for solving a problem in which the flash memory cannot perform a reading process while performing a regeneration process is proposed.